And Indian laboratory has confirmed that drugs used as part of mass sterilizations at a government-run health camp, which killed at least 13 women and made dozens ill, were tainted.

Indian Health Minister of Chattisgarh state, Amar Agrawal, says the antibiotic, ciprocin, which was handed out to dozens of women who underwent sterilization surgeries two weeks ago, contained zinc phosphide, a chemical commonly used in rat poison.

The women started vomiting and complaining of severe pain after taking the medicine at home. In the following days, at least 13 died and many fell seriously ill. The tragedy has raised questions about the practice of conducting mass sterilizations at health camps.

While Indian pharmaceutical companies export billions of dollars’ worth of medicine annually, the tainted ciprocin had been manufactured by Mahawar Pharmaceuticals, a locally-owned company in the central Indian state of Chattisgarh, one of the country's poorest. Mahawar had been sanctioned for making substandard drugs in 2012 and was forced to suspend production for three months. It was recently shuttered and its promoters have been arrested.

Indian Pharmaceutical Association Secretary General D.G. Shah says the tragedy underscores the need for much tighter regulation of these small firms, which, he warns, sometimes do not adhere to "GMT," shorthand for good manufacturing practices.

“They supply to one district or at the most one state or three, four states. They are not national players, and they are governed by the state drug commissioner," he said. "Though on paper they say everybody is complying, they do not comply. As reported in this case, in spite of poor GMT standards, the state drug commissioner had not taken adequate action for closure of this unit. The only positive side we see is that it might act as a wake up call.”

The tragedy has also turned attention to the practice of mass sterilizations carried out at government-run camps, where women are offered a cash incentive of about $10 to undergo tubectomies. There have also been allegations that substandard drugs such as those produced by Mahawar make their way into the state government health facilities in exchange for kickbacks.

Backbone of population control

In the world’s second most populous country of 1.25 billion people, sterilizations continue to be the backbone of population control, although the government denies there is any coercion.

But some advocacy groups say patients aren't given adequate information about alternate methods of contraception by state health workers, who are often under pressure to line up women to undergo tubectomies. The groups have also pointed to the unsanitary conditions in which the surgeries are carried out. The Chattisgarh sterilizations, for example, were done in an unused, private hospital by a doctor who raced through 83 tubectomies in about five hours — about four minutes per patient.

“These camps, they never adhere to those guidelines," said Nibedita Phukan of the New Delhi-based Center for Health and Social Justice. "We have seen lot of camps — Rajasthan, Bihar, Madhya Pradesh, UP. If you go through the guidelines, you cannot operate on any women after 4 o’clock and [not more than 35 women]. Everything has been violated in the mass sterilization camps.”

Recent statistics indicate roughly 4.5 million women were sterilized in India in the year ending in March 2013, but the latest tragedy will likely put the government under pressure to reassess population-control methods.